A new study has found that obesity can shorten one’s life by almost a decade while also vastly reducing quality of life and years of healthy living.

Researchers at McGill University linked obesity with an increased risk of developing heart disease and type 2 diabetes — ailments that dramatically reduce both life expectancy and the number of years spent free of chronic illnesses.

Researchers used data from the U.S. National Health and Nutrition Examination Survey to create a model to estimate the risk of disease based on body weight and then examined how excess weight contributed to years of life lost.

They also calculated the number of years of good health that each individual could — statistically — expect. This was defined as being free of cardiovascular disease or diabetes — two diseases that are closely linked with excessive weight.

Younger age at onset of obesity linked with worse health outcomes

The study found that obese people (with a Body Mass Index of 30 to 34.9) lost between .8 and 5.9 years of life expectancy, while the extremely obese (with a BMI of over 35) lost between .9 and 8.4 years of life expectancy.

The model also found that the younger someone becomes obese, the more years he or she ultimately loses.

“The pattern is clear,” said Dr. Steven Grover, lead author and Professor of Medicine at McGill University. “The more an individual weighs and the younger their age, the greater the effect on their health, as they have many years ahead of them during which the increased health risks associated with obesity can negatively impact their lives.”

According to data from the Centers for Disease Control and Prevention, 69 percent of all adults over the age of 20 are overweight, while 35.1 percent of all adults are obese. Childhood obesity, which has more doubled in the past 30 years, now affects an estimated one in five children and adolescents in the U.S.

“These clinically meaningful models are useful for patients, and their healthcare professionals, to better appreciate the issues and the benefits of a healthier lifestyle, which we know is difficult for many of us to adopt and maintain,” said Dr. Grover.